Verb conjugation of "intervene" in English

Vivi, Sabina and I wanted to thank you very much for Sabina's gift! Thank you for the cool outfits that she is now wearing, all little boys are waiting in line lately. I wish you much happiness.
I am a computer scientist and I also have a small restaurant with my younger sister (she is also already 53). You can come and visit, I will buy you a drink and we could chat a little.
I once had a lesson with a private teacher, but unfortunately she could not come regularly. She was always sick, then I have visited a school in Andalusia, which was worthless, since we talked only German.